I deeply regret my thoughtlessness.

我深为反省自己的轻率。

youdao

What women mistake as thoughtlessness is often just diffidence.

女性误以为是考虑不周的事情往往只是缺乏自信。

youdao

Because rude behavior in children is more often the thoughtlessness than of deliberate aggression , criticism , namecalling and orders only make a child angry and defensive .

孩子的不礼貌行为往往是缺乏考虑的结果，而不是故意冒犯别人，批评辱骂和命令只会使他们恼怒，产生抵触情绪。

youdao

Sir William's point is that the unfairness can often be the result of ignorance or thoughtlessness, not necessarily of a deliberate act.

ECONOMIST: Debating Lawrence | The

Then, one day, the new girl was gone, and the Minotaur worried that, in a moment of thoughtlessness, he had gobbled her up.

NEWYORKER: Ziggurat

Or just pure thoughtlessness?

CENTERFORSECURITYPOLICY: Ayaan Hirsi Ali, abandoned to fanatics